As an aid to the early detection of disease, it has become well established that there are major public health benefits that result from regular endoscopic examination of internal structures, such as the alimentary canals and airways, e.g., the esophagus, stomach, lungs, colon, uterus, ureter, kidney, and other organ systems. A conventional imaging endoscope used for such procedures is formed of a flexible shaft that has a fiber optic light guide that directs illuminating light from an external light source to the distal tip, where it exits the endoscope and illuminates the tissue to be examined. Frequently, additional optical components are incorporated, in order to adjust the spread of light exiting the fiber bundle at the distal tip. An objective lens and fiber optic imaging light guide communicating with a camera at the proximal end of the endoscope or an imaging camera chip installed at the distal tip produces an image that is displayed to the examiner. In addition, most endoscopes include one or more working channels, through which medical devices, such as biopsy forceps, snares, fulguration probes, and other tools, may be passed.
Navigating the endoscope shaft through complex and tortuous paths in a way that produces minimum pain, side effects, risk, or sedation to the patient is critical to the success of the examination. To this end, modem endoscopes include means for deflecting the distal tip of the endoscope to follow the pathway of the structure under examination, with minimum deflection or friction force upon the surrounding tissue. By manipulating a set of control knobs, the examiner is able to steer the endoscope during insertion and direct it to a region of interest, in spite of the limitations of such traditional control systems, which may be clumsy, non-intuitive, and friction-limited.
In any endoscopic procedure, there is almost always a need for the introduction and evacuation of different types of fluids, such as water, saline, drugs, contrast material, dyes, or emulsifiers. For example, one endoscopic procedure is a colonoscopy, which is an internal examination of the colon by means of an instrument called a colonoscope. In colonoscopy procedures, typically 5-10% of patients who arrive for the procedure are inadequately prepared (i.e., the colon is not properly cleared and flushed) and are, therefore, turned away. Some patients who are only marginally unprepared can be fully prepared by a physician or their assistant administering doses of liquid and aspirating the colon. However, these procedures are made more difficult and time consuming because it requires the physician to flush and evacuate stool or other debris, which represents a loss of productivity.
Another endoscopic procedure is an esophagogastroduodenoscopy (EGD), which is an examination of the lining of the esophagus, stomach, and upper duodenum by means of an endoscope that is inserted down the throat. During an EGD procedure, the mixing of bile and water creates a lot of captivating bubbles. These bubbles hinder the physician's visibility during the procedure. As a result, a liquid is often introduced to help reduce the bubbles and, thus, improve visibility.
Yet another endoscopic procedure is an endoscopic retrograde cholangiopancreatography (ERCP), which is an endoscopic procedure used to identify stones, tumors, or narrowing in the bile ducts. In an ERCP procedure, fluids are used to flush away bleeding from sites. In addition, it is sometimes helpful to introduce dyes for providing contrast to the site. Contrast material, or contrast dye, is a substance used to make specific organs, blood vessels, or types of tissue (such as tumors) more visible on X-rays. Common contrast material substances include iodine, barium, and gadolinium.
Conventional endoscopes allow the introduction of liquids via a separate delivery device, such as a syringe or injection catheter that is passed through its working channel, in order to deliver the liquid to the distal tip of the endoscope to the target site within a patient's body. This liquid delivery method involves several steps that include, for example, the user selecting a large capacity syringe (e.g., up to 100 cc), the user pouring a desired liquid into a bowl, the user drawing the liquid into the syringe, the user attaching the syringe to the working channel of the endoscope, and the user squeezing the liquid out of the syringe. This cumbersome and time-consuming process is repeated for any and all types of liquids required in any given endoscopic procedure.
To overcome these and other problems, there is a need for an endoscope having a simplified way to introduce one or more liquids, such as water, saline, drugs, contrast material, dyes, or emulsifiers, that are used in endoscopic procedures, such as a colonoscopy procedure, an EGD procedure, or an ERCP procedure, etc. The endoscopic system should have improved simplicity and ease of use, increased efficiency, and greater clinical productivity and patient throughput. Furthermore, there is a need for improved control of the delivery rate of a liquid and improved mechanisms for mixing two or more fluids. Finally, there is a need for an endoscope that can deliver one or more liquids during a procedure and be inexpensive enough to manufacture that the device can be disposable.